1. Field of the Invention
The present invention relates to an apparatus for orientating rod-like objects, such as cigarettes, and feeding them in the orientated state. More particularly, the present invention relates to an apparatus for orientating a large number of rod-like objects contained in a hopper at random and feeding the rod-like objects in the orientated state.
2. Description of the Related Art
In general, a tobacco wrapping apparatus for producing cigarettes (i.e., rod-like objects) is provided with an apparatus which orientates the cigarettes and feeds them in the orientated state. The tobacco wrapping apparatus comprises a hopper in which a large number of cigarettes are contained at random. A substantially-vertical orientation passage is connected to the hopper, and the upper end of the orientation passage is open in the bottom of the hopper. The orientation passage has a width slightly greater than the diameter of the cigarettes. The cigarettes drop from the hopper into the orientation passage, due to the weight of the cigarettes, and are then fed through the orientation passage while being orientated in the same direction. An arrangement drum is located at the lower end of the orientation passage. The arrangement drum receives, one by one, the cigarettes fed in the orientated state, and arranges them in a predetermined way.
Since the width of the orientation passage is only slightly greater than the diameter of the cigarettes, the cigarettes are likely to jam at the upper end of the orientation passage. This cigarette jam is generally referred to as a "bridge phenomenon" since it is caused by a number of horizontally-orientated cigarettes which are stacked one upon another as if they were stone blocks of an arched bridge. If the bridge phenomenon occurs, the cigarettes in the hopper cannot drop into the orientation passage. The bridge phenomenon is likely to occur particularly in an apparatus adapted to feed cigarettes at high speed.
The bridge phenomenon described above is not the only cause of the cigarettes being prevented from dropping into the orientation passage. That is, when the cigarettes drop through the orientation passage, they may be caught on the wall surface of the orientation passage, thus clogging the orientation passage.
In order to solve the problems, the prior art of the present invention arranges a pair of agitator rollers in the open upper end of the orientation passage and rotates each of the agitator rollers alternately in the normal and reverse directions. With the agitator rollers rotated in this manner, the cigarettes are forcibly guided into the orientation passage.
In addition to the agitator rollers, the prior art to the present invention arranges another pair of agitator rollers or agitator vanes inside the hopper such that the second pair of agitator rollers or vanes are located above the open upper end of the orientation passage. To agitate the cigarettes on the bottom of the hopper, each of the second pair of agitator rollers or vanes is alternately rotated in the normal and reverse directions, thus preventing the occurrence of the bridge phenomenon.